In conference communication services, several participants of a conference are enabled to communicate with one another by means of communication terminals. Participants can be participants of a number of conferences. If a participant participates simultaneously in a number of conferences, only media data from one conference are typically transmitted to him at one time. In particular, the case can occur where media data from a conference are not transmitted to any of the participants since media data are generated at the same time in other conferences in which the participants are participating, and are transmitted to the participants.